The data that old systems contain is very valuable and needs to be used with modern day systems. It would be very costly and time consuming to try to redesign and reprogram all the old systems to output their data to modern day systems. It is equally or even more costly and time consuming to try to print the data to paper and then have to re-enter all the data into the new systems. Since existing printers were designed to output data to paper, they are considered a closed end system with data in and paper out.